CVE-2021-47651 is a vulnerability identified in the Linux kernel, specifically within the Qualcomm (qcom) RPMPD (Remote Power Management Processor Daemon) driver code. The issue arises from improper handling of memory allocation failures in the function that uses devm_kcalloc to allocate memory for data->domains. If devm_kcalloc fails, it returns a NULL pointer, but the existing code does not check for this failure and proceeds to dereference the NULL pointer. This results in a NULL pointer dereference, which can cause a kernel crash (denial of service) or potentially lead to undefined behavior. The vulnerability is rooted in the failure to verify the success of the memory allocation before using the allocated memory, violating safe programming practices in kernel development. The recommended fix involves checking the return value of devm_kcalloc and returning an -ENOMEM error code immediately if the allocation fails, without attempting to manually free the memory, as devm_kmalloc allocations are automatically freed on driver detach. This vulnerability is a stability and reliability issue in the Linux kernel's Qualcomm RPMPD driver and does not appear to have known exploits in the wild at the time of publication. The affected versions are identified by specific commit hashes, indicating that this is a code-level flaw rather than a broadly versioned vulnerability. No CVSS score has been assigned yet, and no evidence suggests privilege escalation or remote code execution capabilities directly from this flaw.

For European organizations, the primary impact of CVE-2021-47651 is the potential for denial of service (DoS) conditions on Linux systems running kernels with the vulnerable Qualcomm RPMPD driver. This could lead to system crashes or instability, affecting availability of critical services, especially in environments where Linux is used in embedded systems, telecommunications infrastructure, or specialized hardware relying on Qualcomm chipsets. While this vulnerability does not directly compromise confidentiality or integrity, the resulting system crashes could disrupt operations, cause downtime, and increase maintenance costs. Organizations in sectors such as telecommunications, industrial control systems, and IoT deployments that utilize Qualcomm-based Linux kernels may be particularly affected. Given the widespread use of Linux in Europe across various industries, any disruption to kernel stability can have cascading effects on business continuity. However, the lack of known exploits and the requirement for local code execution or driver interaction limits the immediate risk of widespread attacks.

To mitigate CVE-2021-47651, European organizations should: 1) Apply the official Linux kernel patches that address this vulnerability as soon as they are released and tested in their environments. 2) For systems using Qualcomm RPMPD drivers, verify kernel versions and update to versions that include the fix. 3) Implement rigorous kernel update policies, especially for embedded and specialized Linux systems, to ensure timely patching. 4) Monitor system logs and kernel crash reports for signs of NULL pointer dereference or unexpected reboots that could indicate exploitation attempts or instability. 5) Employ kernel hardening techniques such as kernel address space layout randomization (KASLR) and control flow integrity (CFI) to reduce the impact of potential kernel faults. 6) Limit access to systems with vulnerable kernels to trusted users and processes to reduce the risk of local exploitation. 7) Conduct thorough testing of kernel updates in staging environments to prevent regression or incompatibility issues in production.